/* ===========================================================================
   ARI homepage — instrument-editorial design system (landing v2).

   Authoritative stylesheet for the bespoke landing page (index.html). The
   docs surface lives in VitePress and consumes ONLY tokens.css through
   .vitepress/theme/brand-bridge.css — never this file.

   DESIGN LANGUAGE — "the paper that runs":
     * typeset technical report: Instrument Serif display, §-numbered section
       heads, FIG.-numbered animation plates, hairline ledger grids;
     * live instrument: IBM Plex Mono readouts, blueprint grid + grain
       backdrop, corner-tick plates, a hero terminal replaying a real run.

   RULE (P1 / L3 brand-token布石): raw hex / rgba color literals live ONLY in
   tokens.css (and SVG asset files / data-URIs, e.g. the grain filter below).
   Everything here references the `--*` tokens.

   CONTRACT: the classes in the "ALGORITHM ANIMATIONS" section are consumed by
   assets/anim/{anim-core,bfts,react,pipeline,virsci}.js — restyle values
   freely, never rename selectors. Same for .demo-video (injected via the
   i18n `dashboard-video` key) and .lang-pill/.is-active (i18n.js).
   =========================================================================== */

/* === base / reset ======================================================== */
*{box-sizing:border-box;margin:0;padding:0;}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%;}
:root{
  --font-serif:'Instrument Serif','Iowan Old Style','Hiragino Mincho ProN','Yu Mincho','Noto Serif JP','Noto Serif SC',Georgia,serif;
  --font-sans:'IBM Plex Sans','Hiragino Kaku Gothic ProN','Yu Gothic','Noto Sans JP','Noto Sans SC',system-ui,sans-serif;
  --font-mono:'IBM Plex Mono','Cascadia Code',ui-monospace,'SFMono-Regular',Menlo,Consolas,monospace;
}
body{
  background:var(--ink);color:var(--text);
  font-family:var(--font-sans);line-height:1.65;
  overflow-x:hidden;position:relative;
}
a{color:var(--cyan-soft);text-decoration:none;}
img,svg,video{max-width:100%;}

/* backdrop: blueprint grid + halos (::before) and film grain (::after).
   Both are fixed, non-interactive, and sit under/over content harmlessly. */
body::before{
  content:'';position:fixed;inset:0;z-index:-1;pointer-events:none;
  background:
    radial-gradient(820px 540px at 12% -4%,var(--halo-cyan),transparent 70%),
    radial-gradient(900px 620px at 88% 12%,var(--halo-blue),transparent 72%),
    linear-gradient(var(--hair-soft) 1px,transparent 1px),
    linear-gradient(90deg,var(--hair-soft) 1px,transparent 1px),
    linear-gradient(var(--grid-line) 1px,transparent 1px),
    linear-gradient(90deg,var(--grid-line) 1px,transparent 1px);
  background-size:auto,auto,256px 256px,256px 256px,64px 64px,64px 64px;
}
body::after{
  content:'';position:fixed;inset:0;z-index:2147483600;pointer-events:none;opacity:.5;
  /* grain texture — inline SVG asset (turbulence → alpha), no color literal */
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0.035 0'/%3E%3C/filter%3E%3Crect width='180' height='180' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* skip-link (a11y) — visually hidden until focused */
.skip-link{position:absolute;left:-9999px;top:0;z-index:2147483601;background:var(--cyan);color:var(--ink);padding:10px 18px;border-radius:0 0 8px 0;font-weight:600;font-family:var(--font-mono);}
.skip-link:focus{left:0;}
:focus-visible{outline:2px solid var(--cyan);outline-offset:2px;}
::selection{background:var(--cyan);color:var(--ink);}

/* === layout utilities ==================================================== */
.container{max-width:1140px;margin:0 auto;padding-left:clamp(18px,4vw,40px);padding-right:clamp(18px,4vw,40px);}
.text-center{text-align:center;}
.mx-auto{margin-left:auto;margin-right:auto;}
.wrap-900{max-width:960px;margin:0 auto;padding-left:clamp(18px,4vw,40px);padding-right:clamp(18px,4vw,40px);}
.max-w-860{max-width:860px;}
.mt-24{margin-top:24px;} .mt-40{margin-top:40px;}
.mb-8{margin-bottom:8px;} .mb-48{margin-bottom:48px;}

/* CJK display tuning — Instrument Serif has no CJK glyphs; the mincho/serif
   fallbacks need looser leading and no negative tracking. */
:lang(ja) .hero h1,:lang(zh) .hero h1{letter-spacing:0;line-height:1.18;max-width:11em;}
:lang(ja) .section-title,:lang(zh) .section-title{letter-spacing:0;line-height:1.25;}
:lang(ja) .phil-quote,:lang(zh) .phil-quote{line-height:1.6;}

/* === NAV ================================================================== */
.site-nav{
  position:fixed;top:0;left:0;right:0;z-index:100;
  -webkit-backdrop-filter:blur(18px);backdrop-filter:blur(18px);
  background:var(--scrim);border-bottom:1px solid var(--hair-soft);
  padding:0 clamp(16px,3vw,32px);height:62px;
  display:flex;align-items:center;justify-content:space-between;gap:16px;
}
.nav-logo{display:flex;align-items:center;gap:10px;font-weight:600;font-size:1rem;font-family:var(--font-mono);letter-spacing:.08em;}
.nav-logo img{width:30px;height:auto;}
.nav-links{display:flex;gap:clamp(14px,2vw,26px);font-family:var(--font-mono);font-size:.72rem;letter-spacing:.12em;text-transform:uppercase;}
.nav-links a{color:var(--muted);position:relative;padding:4px 0;transition:color .2s ease;}
.nav-links a::after{content:'';position:absolute;left:0;right:100%;bottom:0;border-bottom:1px solid var(--cyan);transition:right .25s cubic-bezier(.22,1,.36,1);}
.nav-links a:hover{color:var(--text);}
.nav-links a:hover::after{right:0;}
.nav-cta{
  font-family:var(--font-mono);font-size:.74rem;letter-spacing:.08em;font-weight:600;
  color:var(--cyan-soft);border:1px solid var(--cyan-line);border-radius:8px;
  padding:8px 16px;transition:background .2s ease,color .2s ease;white-space:nowrap;
}
.nav-cta:hover{background:var(--cyan);color:var(--ink);}
/* mobile nav toggle (hamburger) */
.nav-toggle{display:none;background:none;border:1px solid var(--hair);color:var(--text);width:42px;height:42px;border-radius:8px;font-size:1.15rem;cursor:pointer;align-items:center;justify-content:center;}

/* === HERO ================================================================= */
.hero{
  min-height:100vh;min-height:100svh;
  display:flex;flex-direction:column;justify-content:center;
  padding:clamp(120px,16vh,170px) 0 clamp(72px,10vh,110px);
  position:relative;
}
.hero::before{
  content:'';position:absolute;top:-220px;left:50%;transform:translateX(-50%);
  width:min(1100px,120vw);height:780px;pointer-events:none;
  background:radial-gradient(closest-side,var(--blue-glow),transparent 72%);
  opacity:.5;filter:blur(6px);
}
.hero-grid{
  display:grid;grid-template-columns:minmax(0,7fr) minmax(0,5fr);
  gap:clamp(36px,5vw,72px);align-items:center;
  max-width:1140px;margin:0 auto;padding:0 clamp(18px,4vw,40px);
  position:relative;width:100%;
}
.hero img.logo{width:58px;height:auto;display:block;margin-bottom:26px;filter:drop-shadow(0 0 26px var(--cyan-glow));}
.hero-eyebrow{
  font-family:var(--font-mono);font-size:.72rem;font-weight:500;
  letter-spacing:.3em;color:var(--cyan);text-transform:uppercase;margin-bottom:22px;
  display:flex;align-items:center;gap:14px;
}
.hero-eyebrow::after{content:'';flex:0 0 56px;border-top:1px solid var(--cyan-line);}
.hero h1{
  font-family:var(--font-serif);font-weight:400;
  font-size:clamp(2.3rem,1.05rem+4.9vw,5.1rem);line-height:1.02;
  max-width:14ch;
}
.hero-sub{font-size:clamp(.98rem,1.6vw,1.13rem);color:var(--muted);max-width:54ch;margin:26px 0 0;}
.hero-cta{display:flex;gap:14px;align-items:center;flex-wrap:wrap;margin-top:40px;}
.btn-hero{
  font-family:var(--font-mono);font-size:.9rem;font-weight:600;letter-spacing:.02em;
  padding:15px 28px;border-radius:8px;
  transition:transform .2s ease,box-shadow .2s ease,background .2s ease,border-color .2s ease;
}
.btn-hero-primary{background:var(--cyan);color:var(--ink);box-shadow:0 10px 36px var(--cyan-glow);}
.btn-hero-primary:hover{background:var(--cyan-soft);}
.btn-hero-secondary{border:1px solid var(--hair);color:var(--text);background:var(--wash-1);}
.btn-hero-secondary:hover{border-color:var(--cyan-line);box-shadow:3px 3px 0 var(--cyan-wash);}
.hero-more{font-family:var(--font-mono);font-size:.84rem;color:var(--muted);border-bottom:1px dashed var(--muted-2);padding-bottom:2px;transition:color .2s ease,border-color .2s ease;}
.hero-more:hover{color:var(--cyan-soft);border-color:var(--cyan-line);}

/* hero terminal — a decorative replay of one `ari run` (aria-hidden) */
.term-window{
  background:var(--term-bg);border:1px solid var(--hair);border-radius:10px;
  box-shadow:0 30px 90px var(--shadow-deep),inset 0 1px 0 var(--wash-2);
  overflow:hidden;
}
.term-bar{display:flex;align-items:center;gap:9px;padding:11px 14px;border-bottom:1px solid var(--hair-soft);background:var(--wash-1);}
.term-bar::before{content:'●';font-size:.58rem;color:var(--ok);line-height:1;}
.win-file{font-family:var(--font-mono);font-size:.72rem;letter-spacing:.06em;color:var(--muted);}
.term-body{padding:18px 18px 22px;font-family:var(--font-mono);font-size:.8rem;line-height:2;color:var(--text-soft);overflow-x:auto;}
.term-line{white-space:nowrap;}
.term-prompt{color:var(--cyan);margin-right:9px;}
.term-tag{color:var(--cyan-soft);display:inline-block;min-width:5.4em;}
.term-tag::before{content:'[';color:var(--muted-2);}
.term-tag::after{content:']';color:var(--muted-2);margin-right:.6em;}
.term-ok{color:var(--ok-soft);}
.hero-term{transform:rotate(.6deg);transition:transform .4s cubic-bezier(.22,1,.36,1);}
.hero-term:hover{transform:rotate(0deg);}
.caret{display:inline-block;width:9px;height:1.05em;background:var(--cyan);vertical-align:text-bottom;}

.hero-scroll{
  position:absolute;bottom:28px;left:50%;transform:translateX(-50%);
  color:var(--muted-2);font-family:var(--font-mono);font-size:.68rem;letter-spacing:.3em;text-transform:uppercase;
  display:flex;flex-direction:column;align-items:center;gap:8px;
}
.scroll-arrow path{stroke:var(--muted-2);}

/* entrance + caret + scroll motion only when motion is welcome */
@media (prefers-reduced-motion: no-preference){
  .hero-copy > *{animation:rise .85s cubic-bezier(.22,1,.36,1) both;}
  .hero-copy > *:nth-child(1){animation-delay:.05s;}
  .hero-copy > *:nth-child(2){animation-delay:.14s;}
  .hero-copy > *:nth-child(3){animation-delay:.23s;}
  .hero-copy > *:nth-child(4){animation-delay:.32s;}
  .hero-copy > *:nth-child(5){animation-delay:.41s;}
  .hero-side{animation:rise 1s cubic-bezier(.22,1,.36,1) .35s both;}
  .hero-term .term-line{opacity:0;transform:translateY(4px);animation:term-in .5s ease forwards;}
  .hero-term .term-line:nth-child(1){animation-delay:.9s;}
  .hero-term .term-line:nth-child(2){animation-delay:1.25s;}
  .hero-term .term-line:nth-child(3){animation-delay:1.6s;}
  .hero-term .term-line:nth-child(4){animation-delay:1.95s;}
  .hero-term .term-line:nth-child(5){animation-delay:2.3s;}
  .hero-term .term-line:nth-child(6){animation-delay:2.65s;}
  .hero-term .term-line:nth-child(7){animation-delay:3s;}
  .caret{animation:caret-blink 1.1s steps(1) infinite;}
  .hero-scroll{animation:float 2.4s ease-in-out infinite;}
  /* scroll-reveal: armed by the inline IO script; static without JS */
  .reveal-armed [data-reveal]{opacity:0;transform:translateY(18px);transition:opacity .7s cubic-bezier(.22,1,.36,1),transform .7s cubic-bezier(.22,1,.36,1);}
  .reveal-armed [data-reveal].is-vis{opacity:1;transform:none;}
}
@keyframes rise{from{opacity:0;transform:translateY(22px);}to{opacity:1;transform:none;}}
@keyframes term-in{to{opacity:1;transform:none;}}
@keyframes caret-blink{50%{opacity:0;}}
@keyframes float{0%,100%{transform:translateX(-50%) translateY(0);}50%{transform:translateX(-50%) translateY(6px);}}

/* === SECTION SCAFFOLD ===================================================== */
section{padding:clamp(76px,11vw,128px) 0;position:relative;}
.sec-meta{display:flex;align-items:center;gap:14px;margin-bottom:18px;}
.sec-idx{font-family:var(--font-mono);font-size:.72rem;letter-spacing:.22em;color:var(--muted-2);}
.sec-idx::before{content:'§ ';color:var(--cyan);}
.sec-meta::after{content:'';flex:0 0 44px;border-top:1px solid var(--hair);}
.section-label{font-family:var(--font-mono);font-size:.72rem;font-weight:500;letter-spacing:.3em;color:var(--cyan);text-transform:uppercase;}
.section-title{
  font-family:var(--font-serif);font-weight:400;
  font-size:clamp(1.9rem,4.1vw,3.2rem);line-height:1.08;
  margin-bottom:16px;
}
.section-sub{color:var(--muted);font-size:1.02rem;max-width:640px;}
.sec-head{margin-bottom:clamp(36px,5vw,58px);}
.sec-head.is-center{text-align:center;}
.sec-head.is-center .sec-meta{justify-content:center;}
.sec-head.is-center .sec-meta::after{display:none;}
.sec-head.is-center .section-sub{margin-left:auto;margin-right:auto;}

/* instrument plate — hairline frame + cyan corner ticks */
.plate{position:relative;border:1px solid var(--hair);background:var(--ink-2);border-radius:2px;}
.plate::before,.plate::after{content:'';position:absolute;width:16px;height:16px;pointer-events:none;transition:width .25s ease,height .25s ease;}
.plate::before{top:-1px;left:-1px;border-top:2px solid var(--cyan);border-left:2px solid var(--cyan);}
.plate::after{bottom:-1px;right:-1px;border-bottom:2px solid var(--cyan);border-right:2px solid var(--cyan);}
@media (hover:hover){
  .plate:hover::before,.plate:hover::after{width:26px;height:26px;}
}

/* === BUTTON FAMILY (demo / quickstart / community) ======================== */
.btn-row{display:flex;justify-content:center;gap:12px;flex-wrap:wrap;}
.btn-base,.btn-primary,.btn-secondary,.btn-discord{
  font-family:var(--font-mono);font-size:.86rem;font-weight:600;letter-spacing:.01em;
  padding:13px 24px;border-radius:8px;display:inline-block;
  transition:background .2s ease,border-color .2s ease,color .2s ease,box-shadow .2s ease;
}
/* one accent for chrome: a single cyan fill per row, hairline outlines for
   the rest (in-system hover: cyan hairline + offset tick shadow) */
.btn-solid{background:var(--cyan);color:var(--ink);box-shadow:0 8px 30px var(--cyan-glow);}
.btn-solid:hover{background:var(--cyan-soft);}
.btn-outline{border:1px solid var(--hair);color:var(--text);}
.btn-outline:hover{border-color:var(--cyan-line);box-shadow:3px 3px 0 var(--cyan-wash);}
.btn-discord{background:var(--discord);color:var(--white);}
.btn-discord:hover{box-shadow:3px 3px 0 var(--wash-2);}
.btn-primary{background:var(--cyan);color:var(--ink);}
.btn-primary:hover{background:var(--cyan-soft);}
.btn-secondary{border:1px solid var(--hair);color:var(--text);}
.btn-secondary:hover{border-color:var(--cyan-line);box-shadow:3px 3px 0 var(--cyan-wash);}

/* === DEMO ================================================================= */
.demo{background:linear-gradient(180deg,transparent 0%,var(--ink-2) 100%);border-top:1px solid var(--hair-soft);}
.demo-sub{margin-left:auto;margin-right:auto;margin-bottom:44px;}
.demo-video-wrap{margin:0 auto 14px;max-width:920px;padding:10px;}
.demo-video{display:block;width:100%;border-radius:2px;background:var(--black);}
.demo-watch{font-family:var(--font-mono);font-size:.72rem;letter-spacing:.06em;color:var(--muted-2);margin-bottom:30px;}
.demo-watch::before{content:'▸ ';color:var(--cyan);}

/* sample paper viewer — pre-rendered pages of assets/sample_paper.pdf in a
   scrollable instrument window (the dogfooded paper, not the System Report) */
.paper-window{max-width:760px;margin:64px auto 0;text-align:left;}
.term-bar .bar-link{margin-left:auto;font-family:var(--font-mono);font-size:.7rem;font-weight:600;color:var(--cyan-soft);}
.term-bar .bar-link:hover{text-decoration:underline;}
.paper-pages{height:min(72vh,820px);overflow-y:auto;background:var(--panel-wash);padding:clamp(14px,2.5vw,28px);scrollbar-width:thin;}
.paper-page{display:block;width:100%;max-width:640px;height:auto;margin:0 auto 18px;border-radius:2px;box-shadow:0 10px 34px var(--shadow-deep);}
.paper-page:last-child{margin-bottom:0;}
.paper-note{font-family:var(--font-mono);font-size:.72rem;color:var(--muted-2);margin-top:14px;max-width:640px;margin-left:auto;margin-right:auto;}
.demo .btn-row{margin-bottom:0;}

/* the paper sheet — a lit page on the dark bench (System Report, P6) */
.paper-sheet{
  background:var(--paper);color:var(--paper-ink);border-radius:3px;
  max-width:880px;margin:72px auto 0;padding:clamp(28px,4.5vw,52px);
  box-shadow:0 34px 90px var(--shadow-deep);
  position:relative;text-align:center;
}
.paper-sheet::before{content:'';position:absolute;top:0;left:0;right:0;height:3px;background:linear-gradient(90deg,var(--cyan),var(--blue));}
/* running foot — typeset-page furniture; language-neutral (CSS bypasses i18n) */
.paper-sheet::after{
  content:'ARI · SYSTEM REPORT · EN / JA / ZH';display:block;margin-top:30px;padding-top:14px;
  border-top:1px solid var(--paper-line);
  font-family:var(--font-mono);font-size:.6rem;letter-spacing:.28em;color:var(--paper-muted);
}
.demo-inline-title{font-family:var(--font-serif);font-weight:400;font-size:clamp(1.4rem,2.6vw,1.8rem);margin-bottom:10px;}
.demo-inline-sub{color:var(--paper-muted);font-size:.92rem;max-width:560px;margin:0 auto 28px;}
.report-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;}
.report-card{border:1px solid var(--paper-line);border-radius:3px;padding:20px 22px;text-align:left;transition:border-color .2s ease,box-shadow .2s ease;background:transparent;}
.report-card:hover{border-color:var(--blue);box-shadow:3px 3px 0 var(--paper-wash);}
.report-card.is-default{border-color:var(--blue);box-shadow:0 0 0 3px var(--blue-ring);}
.report-card .report-lang{font-family:var(--font-mono);font-size:.66rem;font-weight:600;letter-spacing:.18em;color:var(--cyan-deep);text-transform:uppercase;}
.report-card h4{font-weight:600;font-size:.98rem;margin:8px 0 10px;}
.report-card a{font-family:var(--font-mono);font-size:.8rem;font-weight:600;color:var(--blue);}
.report-card a:hover{text-decoration:underline;}

/* === PHILOSOPHY =========================================================== */
.phil-quote{
  font-family:var(--font-serif);font-style:italic;font-weight:400;
  font-size:clamp(1.45rem,3vw,2.15rem);line-height:1.35;color:var(--text-soft2);
  border-left:2px solid var(--cyan);padding:10px 0 10px clamp(22px,3vw,36px);
  margin:44px 0;max-width:780px;position:relative;
}
.phil-quote::before{
  content:'\201C';position:absolute;top:-38px;left:-14px;
  font-size:7rem;line-height:1;color:var(--cyan);opacity:.16;font-style:normal;
  pointer-events:none;
}
.phil-body{color:var(--text-soft);font-size:1.02rem;max-width:720px;}
.phil-body p+p{margin-top:18px;}

/* === INSPIRED / PRIOR WORK — a reference ledger =========================== */
.inspired{border-top:1px solid var(--hair-soft);}
.card-grid{
  display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));
  gap:1px;background:var(--hair-soft);border:1px solid var(--hair-soft);
}
.card{background:var(--ink);padding:30px 28px 28px;position:relative;transition:background .25s ease;}
.card::before{content:'';position:absolute;top:-1px;left:-1px;width:0;height:0;border-top:2px solid var(--cyan);border-left:2px solid var(--cyan);transition:width .25s ease,height .25s ease;pointer-events:none;}
@media (hover:hover){
  .card:hover{background:var(--surface);}
  .card:hover::before{width:22px;height:22px;}
}
.card-ref{font-family:var(--font-mono);font-size:.76rem;color:var(--cyan);margin-bottom:14px;letter-spacing:.06em;}
.card-title{font-family:var(--font-serif);font-weight:400;font-size:1.35rem;margin-bottom:10px;}
.card-desc{color:var(--muted);font-size:.88rem;line-height:1.7;margin-bottom:18px;}
.card-desc code{font-family:var(--font-mono);font-size:.92em;color:var(--accent);background:var(--wash-1);padding:1px 5px;border-radius:4px;}
.card-desc a{color:var(--cyan-soft);}
.card-link{font-family:var(--font-mono);font-size:.76rem;color:var(--cyan-soft);letter-spacing:.02em;}
.card-link:hover{text-decoration:underline;}

/* === HOW IT WORKS ========================================================= */
.how{background:linear-gradient(180deg,var(--ink-2) 0%,transparent 18%);border-top:1px solid var(--hair-soft);counter-reset:fig;}
.steps{
  display:grid;grid-template-columns:repeat(3,1fr);
  border:1px solid var(--hair-soft);background:var(--hair-soft);gap:1px;
  margin-top:8px;
}
.step{background:var(--ink);padding:26px 24px 30px;position:relative;}
.step-no{font-family:var(--font-mono);font-size:.74rem;letter-spacing:.18em;color:var(--muted-2);display:block;margin-bottom:16px;}
.step-no::after{content:'';display:block;width:26px;border-top:1px solid var(--hair);margin-top:8px;transition:width .25s ease,border-color .25s ease;}
@media (hover:hover){
  .step:hover .step-no::after{width:44px;border-color:var(--cyan-line);}
}
.step h3{font-family:var(--font-serif);font-weight:400;font-size:1.3rem;margin-bottom:8px;}
.step p{font-size:.85rem;color:var(--muted);line-height:1.7;}
.step.is-core{background:linear-gradient(180deg,var(--blue-wash) 0%,var(--ink) 86%);}
.step-core{
  position:absolute;top:24px;right:22px;
  font-family:var(--font-mono);font-size:.62rem;font-weight:600;letter-spacing:.22em;
  color:var(--cyan);border:1px solid var(--cyan-line);border-radius:4px;padding:3px 8px;
}

/* === ALGORITHM ANIMATIONS (§8) — figure plates ============================ */
/* CONTRACT SECTION: selectors below are consumed by assets/anim/*.js.       */
.anim-block, .algo-anim{
  margin:64px auto 0;max-width:780px;text-align:center;
  border:1px solid var(--hair-soft);border-radius:2px;
  /* top-left corner tick drawn as background layers (::before holds FIG.) */
  background:
    linear-gradient(var(--cyan),var(--cyan)) top left/16px 2px no-repeat border-box,
    linear-gradient(var(--cyan),var(--cyan)) top left/2px 16px no-repeat border-box,
    var(--ink-2);
  padding:26px clamp(14px,3vw,30px) 28px;position:relative;
  counter-increment:fig;
}
.anim-block::before{
  content:'FIG. ' counter(fig,decimal-leading-zero);
  display:block;font-family:var(--font-mono);font-size:.66rem;font-weight:600;
  letter-spacing:.3em;color:var(--cyan);margin-bottom:14px;
}
.anim-block::after{
  content:'';position:absolute;bottom:-1px;right:-1px;width:16px;height:16px;
  border-bottom:2px solid var(--cyan);border-right:2px solid var(--cyan);pointer-events:none;
}
.anim-title{font-family:var(--font-serif);font-weight:400;font-size:1.3rem;margin-bottom:6px;}
.anim-desc{font-size:.85rem;color:var(--muted);max-width:600px;margin:0 auto 18px;}
.anim-svg{width:100%;height:auto;display:block;background:var(--panel-wash);border:1px solid var(--border);border-radius:2px;}
#anim-bfts .anim-svg{aspect-ratio:76/48;}
#anim-react .anim-svg{aspect-ratio:48/36;max-width:520px;margin:0 auto;}
#anim-virsci .anim-svg{aspect-ratio:64/28;}
#anim-pipeline .anim-svg{aspect-ratio:115/21;}

/* nodes / edges */
.anim-edge{stroke:var(--border);stroke-width:2;transition:opacity .5s ease;}
.anim-edge.is-dashed{stroke:var(--danger-soft);stroke-dasharray:6 5;}
.anim-edge.is-hidden{opacity:0;}
/* solid edges carry pathLength="1" (set by the anim modules) so reveal can
   draw the line from the parent node instead of popping it in */
.anim-edge[pathLength]{stroke-dasharray:1;stroke-dashoffset:0;transition:stroke-dashoffset .7s cubic-bezier(.22,1,.36,1) .15s,opacity .35s ease;}
.anim-edge[pathLength].is-hidden{stroke-dashoffset:1;}
.anim-node{transition:opacity .5s cubic-bezier(.22,1,.36,1),transform .5s cubic-bezier(.34,1.56,.64,1);transform-box:fill-box;transform-origin:center;}
.anim-node.is-hidden{opacity:0;transform:scale(.55);}
.anim-dot{fill:var(--surface2);stroke:var(--border);stroke-width:2;transition:fill .5s ease,stroke .5s ease;}
.anim-node.is-success .anim-dot{fill:var(--ok);stroke:var(--ok);}
.anim-node.is-failed  .anim-dot{fill:var(--danger);stroke:var(--danger);}
.anim-node.is-running .anim-dot{fill:var(--blue-light);stroke:var(--blue-light);animation:anim-pulse 1.3s ease-in-out infinite;}
.anim-node.is-pending .anim-dot{fill:var(--muted-2);stroke:var(--muted-2);}
.anim-node-label{fill:var(--white);font-size:13px;font-weight:600;text-anchor:middle;font-family:var(--font-mono);}
.anim-score{fill:var(--text-soft);font-size:13px;text-anchor:middle;font-family:var(--font-mono);}
.anim-ring{fill:none;stroke:var(--accent);stroke-width:2.5;stroke-dasharray:5 5;opacity:0;transition:opacity .4s ease;}
.anim-node.has-ring .anim-ring{opacity:1;animation:anim-ring-spin 3.5s linear infinite;}
.anim-node.is-retired{opacity:.4;}
.anim-node.is-best .anim-dot{stroke:var(--grad-b);stroke-width:4;filter:drop-shadow(0 0 8px var(--grad-b));animation:anim-best-glow 2.4s ease-in-out infinite;}
@keyframes anim-ring-spin{to{stroke-dashoffset:-40;}}
@keyframes anim-pulse{0%,100%{opacity:1;}50%{opacity:.55;}}
@keyframes anim-best-glow{0%,100%{filter:drop-shadow(0 0 6px var(--grad-b));}50%{filter:drop-shadow(0 0 16px var(--grad-b));}}
/* flowing dashes along an active edge — dasharray period must divide 24 */
@keyframes anim-dash-flow{to{stroke-dashoffset:-24;}}

/* controls + status + legend */
.anim-controls{display:flex;justify-content:center;gap:10px;margin:16px 0 6px;}
.anim-ctl{min-width:44px;min-height:44px;border-radius:8px;background:var(--wash-1);border:1px solid var(--hair);color:var(--text);font-size:1rem;cursor:pointer;transition:border-color .15s ease,background .15s ease;}
.anim-ctl:hover{border-color:var(--cyan-line);background:var(--blue-wash);}
.anim-status{font-family:var(--font-mono);font-size:.78rem;color:var(--text-soft);min-height:1.5em;max-width:600px;margin:0 auto;}
.anim-caption{font-family:var(--font-mono);font-size:.68rem;color:var(--muted-2);max-width:640px;margin:16px auto 0;line-height:1.6;}
.anim-legend{list-style:none;display:flex;flex-wrap:wrap;justify-content:center;gap:8px 16px;margin:14px auto 0;max-width:640px;font-family:var(--font-mono);font-size:.7rem;color:var(--muted);}
.anim-legend li{display:flex;align-items:center;gap:6px;}
.anim-legend .anim-lg-type{color:var(--text-soft);}
.anim-swatch{width:11px;height:11px;border-radius:50%;display:inline-block;}
.anim-swatch.is-success{background:var(--ok);} .anim-swatch.is-failed{background:var(--danger);}
.anim-swatch.is-running{background:var(--blue-light);} .anim-swatch.is-pending{background:var(--muted-2);}

/* ReAct */
.rk-node{fill:none;stroke:var(--border);stroke-width:1.5;}
.rk-node-label{fill:var(--muted);font-size:13px;}
.rk-step{fill:var(--accent);font-size:14px;font-weight:600;font-family:var(--font-mono);}
.rk-rect{fill:var(--surface2);stroke:var(--border);stroke-width:1.5;transition:fill .4s ease,stroke .4s ease;}
.rk-label{fill:var(--text);font-size:15px;font-weight:600;text-anchor:middle;}
.rk-box{transition:transform .35s cubic-bezier(.22,1,.36,1);transform-box:fill-box;transform-origin:center;}
.rk-box.is-active{transform:scale(1.05);}
.rk-box.is-active .rk-rect{fill:var(--blue-wash-2);stroke:var(--blue-light);}
.rk-poll .rk-rect{stroke-dasharray:5 4;}
.rk-poll.is-active .rk-rect{fill:var(--purple-wash);stroke:var(--purple);}
.rk-tool{fill:var(--accent);font-size:12px;font-family:var(--font-mono);}
.rk-arrow{stroke:var(--muted-2);stroke-width:2;}
.rk-arrow.rk-async{stroke:var(--purple);stroke-dasharray:5 4;}
.rk-feedback{fill:none;stroke:var(--muted-2);stroke-width:2;opacity:.35;transition:opacity .4s ease,stroke .4s ease;}
.rk-feedback.is-active{opacity:1;stroke:var(--blue-light);stroke-dasharray:6 6;animation:anim-dash-flow .9s linear infinite;}
.rk-json{fill:var(--ok-soft);font-size:14px;font-family:var(--font-mono);}

/* Pipeline */
.pl-seg{stroke:var(--border);stroke-width:3;transition:stroke .4s ease;}
.pl-seg.is-done{stroke:var(--blue);}
.pl-dot{fill:var(--surface2);stroke:var(--border);stroke-width:2;transition:fill .4s ease,stroke .4s ease;}
.pl-step.is-done .pl-dot{fill:var(--blue-wash-2);stroke:var(--blue);}
.pl-step.is-current .pl-dot{fill:var(--blue-wash-2);stroke:var(--blue-light);animation:anim-pulse 1.6s ease-in-out infinite;}
.pl-num{fill:var(--text);font-size:22px;font-weight:700;font-family:var(--font-mono);}
.pl-label{fill:var(--muted);font-size:18px;}
.pl-mini{transition:opacity .4s ease;}
.pl-mini.is-hidden{opacity:0;}
.pl-mini-dot{fill:var(--surface2);stroke:var(--border);stroke-width:2;transition:fill .4s ease;}
.pl-mini-dot.is-running{fill:var(--blue-light);stroke:var(--blue-light);animation:anim-pulse 1.3s ease-in-out infinite;}
.pl-mini-dot.is-success{fill:var(--ok);stroke:var(--ok);}
.pl-mini-dot.is-failed{fill:var(--danger);stroke:var(--danger);}
.pl-mini-dot.is-pending{fill:var(--muted-2);stroke:var(--muted-2);}
.pl-mini-dot.is-hidden{opacity:0;}

/* VirSci */
.vs-survey{opacity:.3;transition:opacity .4s ease;}
.vs-survey.is-on{opacity:1;}
.vs-link{stroke:var(--accent);stroke-width:2;stroke-dasharray:4 4;}
.vs-survey.is-on .vs-link{animation:anim-dash-flow 1.2s linear infinite reverse;}
.vs-survey-dot{fill:var(--blue-wash-2);stroke:var(--blue-light);stroke-width:2;}
.vs-survey-tx{font-size:16px;}
.vs-edge{stroke:var(--border);stroke-width:2;opacity:.3;transition:opacity .4s ease,stroke .4s ease;}
.vs-edge.is-active{opacity:1;stroke:var(--blue-light);stroke-width:3;stroke-dasharray:6 6;animation:anim-dash-flow .9s linear infinite;}
.vs-dot{fill:var(--surface2);stroke:var(--border);stroke-width:2;transition:fill .4s ease,stroke .4s ease;}
.vs-pers{transition:transform .35s cubic-bezier(.22,1,.36,1);transform-box:fill-box;transform-origin:center;}
.vs-pers.is-active{transform:scale(1.08);}
.vs-pers.is-active .vs-dot{fill:var(--blue-wash-2);stroke:var(--blue-light);}
.vs-pers-label{fill:var(--text);font-size:13px;font-weight:600;}
.vs-draft-rect{fill:var(--surface);stroke:var(--border);stroke-width:2;transition:stroke .4s ease;}
.vs-draft.is-best .vs-draft-rect{stroke:var(--grad-b);stroke-width:3;filter:drop-shadow(0 0 6px var(--grad-b));animation:anim-best-glow 2.4s ease-in-out infinite;}
.vs-draft-label{fill:var(--text);font-size:13px;font-weight:700;}
.vs-score{fill:var(--ok-soft);font-size:13px;font-weight:600;font-family:var(--font-mono);}
.vs-dims{fill:var(--muted);font-size:10px;font-family:var(--font-mono);}
.vs-tobfts{transition:opacity .45s ease,transform .55s cubic-bezier(.22,1,.36,1);transform-box:fill-box;transform-origin:center;}
.vs-tobfts.is-hidden{opacity:0;transform:translateX(-14px);}
.vs-bf-arrow{stroke:var(--grad-b);stroke-width:2.5;}
.vs-bf-tx{fill:var(--grad-b);font-size:12px;font-weight:700;}

/* === DASHBOARD CONSOLE ==================================================== */
.dashboard-highlight{
  margin-top:72px;border:1px solid var(--hair);border-radius:2px;
  background:linear-gradient(180deg,var(--wash-1) 0%,transparent 60%);
  padding:clamp(28px,4.5vw,48px);text-align:center;position:relative;
}
.dashboard-highlight::before{content:'';position:absolute;top:-1px;left:-1px;width:16px;height:16px;border-top:2px solid var(--cyan);border-left:2px solid var(--cyan);}
.dashboard-highlight::after{content:'';position:absolute;bottom:-1px;right:-1px;width:16px;height:16px;border-bottom:2px solid var(--cyan);border-right:2px solid var(--cyan);}
.dash-code{
  display:inline-block;font-family:var(--font-mono);font-size:.66rem;font-weight:600;
  letter-spacing:.26em;color:var(--cyan);border:1px solid var(--cyan-line);
  border-radius:4px;padding:4px 12px;margin-bottom:18px;text-transform:uppercase;
}
.dashboard-highlight h3{font-family:var(--font-serif);font-weight:400;font-size:clamp(1.4rem,2.6vw,1.8rem);margin-bottom:14px;}
.dashboard-desc{color:var(--muted);max-width:680px;margin:0 auto 24px;font-size:.93rem;line-height:1.75;}
.dashboard-see{font-family:var(--font-mono);font-size:.78rem;color:var(--muted);margin-bottom:20px;}
.dashboard-see::before{content:'▸ ';color:var(--cyan);}
.dashboard-see a{color:var(--cyan-soft);}
.pill-row{display:flex;justify-content:center;gap:10px;flex-wrap:wrap;}
.pill{font-family:var(--font-mono);font-size:.74rem;background:var(--blue-wash);color:var(--accent);padding:6px 14px;border-radius:4px;border:1px solid var(--hair-soft);}
.mono-box{
  margin-top:26px;font-family:var(--font-mono);font-size:.86rem;color:var(--cyan-soft);
  background:var(--term-bg);border:1px solid var(--hair);border-radius:10px;
  padding:14px 24px;display:inline-block;
}
.mono-box::before{content:'$ ';color:var(--muted-2);}

/* === UNIVERSAL ============================================================ */
.universal{border-top:1px solid var(--hair-soft);}
.axis-grid{
  display:grid;grid-template-columns:repeat(auto-fit,minmax(208px,1fr));
  gap:1px;background:var(--hair-soft);border:1px solid var(--hair-soft);
  margin-top:48px;
}
.axis-card{background:var(--ink);padding:28px 24px;transition:background .25s ease;position:relative;}
.axis-card.is-compact{padding:26px 24px;}
@media (hover:hover){
  .axis-card:hover{background:var(--surface);}
}
.axis-code{
  display:inline-block;font-family:var(--font-mono);font-size:.64rem;font-weight:600;
  letter-spacing:.24em;color:var(--cyan);border:1px solid var(--cyan-line);
  border-radius:4px;padding:3px 9px;margin-bottom:16px;
}
.axis-card h3{font-size:1rem;font-weight:600;margin-bottom:8px;}
.axis-card p{font-size:.86rem;color:var(--muted);line-height:1.65;}
.axis-range{
  display:inline-block;font-family:var(--font-mono);font-size:.68rem;color:var(--cyan-soft);
  letter-spacing:.04em;background:var(--cyan-wash);padding:4px 10px;border-radius:4px;margin-top:14px;
}

/* === FUTURE / VISION ====================================================== */
.future-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(228px,1fr));gap:16px;margin-top:48px;}
.future-card{border:1px dashed var(--hair);border-radius:2px;padding:26px 24px;transition:border-color .2s ease,background .2s ease;}
@media (hover:hover){
  .future-card:hover{border-color:var(--cyan-line);background:var(--wash-1);}
}
.future-tag{font-family:var(--font-mono);font-size:.64rem;font-weight:600;letter-spacing:.2em;color:var(--cyan-soft);text-transform:uppercase;margin-bottom:14px;}
.future-card h3{font-size:1rem;font-weight:600;margin-bottom:8px;}
.future-card p{font-size:.85rem;color:var(--muted);line-height:1.65;}
.roadmap-flag{font-family:var(--font-mono);font-size:.66rem;color:var(--danger-soft);font-weight:500;}

/* === QUICK START ========================================================== */
.qs{background:linear-gradient(180deg,var(--ink-2) 0%,transparent 30%);border-top:1px solid var(--hair-soft);}
.qs-grid{display:grid;grid-template-columns:1.04fr .96fr;gap:clamp(22px,3vw,40px);margin-top:8px;align-items:start;}
.qs-exp-intro{font-family:var(--font-mono);font-size:.8rem;color:var(--muted);margin-bottom:14px;}
pre{
  background:transparent;font-family:var(--font-mono);font-size:.8rem;line-height:1.8;
  overflow-x:auto;padding:20px 22px;color:var(--text-soft2);
  -webkit-overflow-scrolling:touch;
}
.term-window pre{margin:0;}
.comment{color:var(--comment);}
.qs-note{margin-top:20px;color:var(--muted);font-size:.9rem;}
.qs-note strong{color:var(--text);}

/* === COMMUNITY ============================================================ */
.community{border-top:1px solid var(--hair-soft);}
.comm-grid{
  display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));
  gap:1px;background:var(--hair-soft);border:1px solid var(--hair-soft);
  text-align:left;
}
.comm-code{
  display:inline-block;font-family:var(--font-mono);font-size:.68rem;font-weight:600;
  letter-spacing:.1em;color:var(--cyan);margin-bottom:14px;
}
.comm-grid h3{font-size:1rem;font-weight:600;margin-bottom:8px;}
.comm-grid p{font-size:.86rem;color:var(--muted);line-height:1.65;}

/* === FOOTER (colophon) ==================================================== */
footer{border-top:1px solid var(--hair-soft);padding:56px 24px 46px;text-align:center;color:var(--muted);font-size:.88rem;}
footer .footer-logo{display:flex;align-items:center;gap:10px;justify-content:center;font-family:var(--font-mono);font-weight:600;letter-spacing:.04em;color:var(--text);margin-bottom:16px;font-size:.92rem;}
footer img{width:24px;height:auto;}
footer p{margin-top:8px;font-family:var(--font-mono);font-size:.78rem;}
footer a{color:var(--muted);border-bottom:1px dotted var(--muted-2);transition:color .2s ease;}
footer a:hover{color:var(--cyan-soft);}
.footer-tagline{margin-top:14px;font-family:var(--font-serif);font-style:italic;font-size:.98rem;color:var(--muted);}

/* === LANGUAGE SWITCHER ==================================================== */
.langbar{
  position:fixed;bottom:calc(18px + env(safe-area-inset-bottom,0px));right:18px;z-index:2147483647;
  display:flex;flex-direction:row;gap:5px;background:var(--scrim);
  border:1px solid var(--hair);padding:5px 8px;border-radius:30px;
  box-shadow:0 4px 20px var(--shadow-soft);
  -webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);
}
.lang-pill{font-family:var(--font-mono);background:var(--wash-2);border:1px solid var(--wash-3);color:var(--text);padding:4px 12px;border-radius:20px;font-size:.74rem;font-weight:600;cursor:pointer;transition:background .15s ease,color .15s ease;}
.lang-pill:hover{background:var(--wash-3);}
.lang-pill.is-active{background:var(--cyan);border-color:var(--cyan);color:var(--ink);}
[data-lang]:not(.lang-active){display:none!important;}

/* =========================================================================
   MOTION SAFETY — kill every animation/transition under reduced motion.
   (Entrance/reveal effects are additionally gated on no-preference above,
   so content is never hidden when motion is off.)
   ========================================================================= */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto;}
  *,*::before,*::after{animation:none!important;transition:none!important;}
}

/* =========================================================================
   RESPONSIVE LADDER — 1180 / 1020 / 900 / 700 / 560 / 420 / short viewports
   ========================================================================= */
@media (max-width:1180px){
  .hero-grid{gap:36px;}
}
@media (max-width:1020px){
  .hero{min-height:0;padding-top:130px;}
  .hero-grid{grid-template-columns:1fr;gap:44px;}
  .hero-side{max-width:560px;width:100%;}
  .hero-term{transform:none;}
  .hero-scroll{display:none;}
  .qs-grid{grid-template-columns:1fr;}
}
@media (max-width:900px){
  .steps{grid-template-columns:repeat(2,1fr);}
  .card-grid{grid-template-columns:repeat(auto-fit,minmax(min(260px,100%),1fr));}
  .report-grid{grid-template-columns:1fr;gap:10px;}
  .paper-sheet{margin-top:56px;}
  .phil-quote::before{font-size:5rem;top:-26px;left:-8px;}
  section{padding:clamp(64px,9vw,96px) 0;}
}
/* nav collapses earlier than the content ladder: with 7 mono links the bar
   needs ~860px (EN) before links start wrapping inside the 62px bar */
@media (max-width:860px){
  .nav-toggle{display:flex;}
  .nav-links{
    position:absolute;top:100%;left:0;right:0;flex-direction:column;gap:0;
    background:var(--scrim);-webkit-backdrop-filter:blur(18px);backdrop-filter:blur(18px);
    border-bottom:1px solid var(--hair);padding:8px 0;display:none;
  }
  .nav-links.is-open{display:flex;}
  .nav-links a{padding:13px 24px;}
  .nav-links a::after{display:none;}
}
@media (max-width:700px){
  .site-nav{height:58px;padding:0 16px;}
  .nav-cta{display:none;}
  .hero{padding-top:108px;}
  .hero img.logo{width:48px;}
  .hero-eyebrow{font-size:.64rem;letter-spacing:.22em;}
  .term-body{font-size:.72rem;padding:14px 14px 18px;}
  .demo-video-wrap{padding:7px;}
  .dashboard-highlight{margin-top:56px;}
  .paper-window{margin-top:48px;}
  .paper-pages{height:min(64vh,560px);}
  .anim-block,.algo-anim{margin-top:48px;}
  .anim-legend{flex-direction:column;align-items:flex-start;text-align:left;max-width:300px;}
  .anim-caption{font-size:.62rem;}
  .future-grid{gap:12px;}
  footer{padding:44px 18px 40px;}
}
@media (max-width:560px){
  .steps{grid-template-columns:1fr;}
  .step{padding:22px 20px 24px;}
  .hero-cta{flex-direction:column;align-items:stretch;}
  .btn-hero{text-align:center;}
  .hero-more{align-self:center;}
  .btn-row{flex-direction:column;align-items:stretch;}
  .btn-row .btn-base,.btn-row .btn-primary,.btn-row .btn-secondary,.btn-row .btn-discord{text-align:center;}
  .paper-sheet{padding:24px 18px 26px;}
  .report-card{padding:16px 18px;}
  .pill-row{gap:8px;}
  .pill{font-size:.68rem;padding:5px 11px;}
  .mono-box{font-size:.74rem;padding:12px 16px;max-width:100%;overflow-x:auto;}
  .phil-quote{margin:32px 0;}
  .sec-meta::after{flex-basis:28px;}
  .langbar{right:12px;padding:4px 7px;}
  .lang-pill{padding:3px 10px;font-size:.7rem;}
  /* clear the fixed langbar so it never sits on the footer tagline */
  footer{padding-bottom:96px;}
}
@media (max-width:420px){
  .section-title{font-size:1.7rem;}
  .container,.wrap-900{padding-left:16px;padding-right:16px;}
  .hero-grid{padding:0 16px;}
  .term-tag{min-width:0;}
  pre{font-size:.72rem;padding:16px 14px;}
  .anim-ctl{min-width:42px;min-height:42px;}
  .footer-logo{flex-direction:column;gap:8px;}
}
/* short landscape viewports — keep the hero from overflowing */
@media (max-height:620px) and (min-width:701px){
  .hero{min-height:0;padding:120px 0 64px;}
  .hero-scroll{display:none;}
}